Molecular self-assembly has been defined as “the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds.” Whitesides et al., Science (1991) 254:1312–1319. Many examples of self-assembly occur in biology, including amphiphilic bilayers in cell membranes, the T4 phage particle, and the transmembrane toxin α-hemolysin. One of the most important aspects of self-assembly is the fact that the final biological structures are generally self-healing and relatively defect-free. This feature is a result of the thermodynamic processes that drive the self-assembly process. In addition, the aforementioned biological structures spontaneously assemble in the correct order and into the correct configuration without the need for complex atom-by-atom synthesis. The above attributes of biological self-assembly are some of the motivating factors that have prompted researches to attempt to mimic self-assembly systems in the laboratory via synthetic routes.
For the purposes of nanofabrication, chemical self-assembly has several advantages. One advantage is that nanoscale objects are synthesized spontaneously, without the need for expensive or elaborate equipment. Another advantage is that construction of nanostructures using atom-by-atom protocols can be extremely time consuming and resource intensive, if not impossible to perform.
While self-assembly of nanostructures is of great interest, the majority of work to date has focused on the self-assembly of solid nanostructures. In certain applications, porous nanostructures are desired. While attempts to produce porous nanostructures via self-assembly protocols have been made, such have not been completely successful. For example, the porosity of such structures may be inconsistent, the pore diameter may be too large, etc.
As such, there is a need for nano-objects and durable membrane structures with internal nanopores offering the characteristics of electrical reliability, as well as consistent overall size and pore diameter. In addition, there is also a need for durable nanoporous membrane structures. The present invention satisfies these, and other, needs.
Relevant Literature
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